When you're working with files, it is sometimes necessary to write to temporary files. Of course you could drop those files in the application's folder, but it's good practice to save those files in the user's Temp folder instead. This snippet will return the full path to the user's temp folder, e.g.
C:\Documents and Settings\Imar\Local Settings\Temp\, so you know where to save your temporary files.
For this code to work, you'll need to import the System.IO namespace.